Added pageup/pagedown functionality.

src/editor.rs

@@ -148,4 +148,52 @@ impl Editor {
         
         self.move_view_to_cursor();
     }
+    
+    pub fn page_up(&mut self) {
+        if self.view_pos.0 > 0 {
+            let move_amount = self.view_dim.0 - (self.view_dim.0 / 8);
+            if self.view_pos.0 >= move_amount {
+                if self.cursor.0 >= move_amount {
+                    self.cursor.0 -= move_amount;
+                }
+                self.view_pos.0 -= move_amount;
+            }
+            else {
+                if self.cursor.0 >= self.view_pos.0 {
+                    self.cursor.0 -= self.view_pos.0;
+                }
+                else {
+                    self.cursor = (0, 0);
+                }
+                self.view_pos.0 = 0;
+            }   
+        }
+        else {
+            self.cursor = (0, 0);
+        }
+    }
+    
+    pub fn page_down(&mut self) {
+        let nlc = self.buffer.newline_count();
+        
+        if self.view_pos.0 < nlc {
+            let move_amount = self.view_dim.0 - (self.view_dim.0 / 8);
+            let max_move = nlc - self.view_pos.0;
+            let cursor_max_move = nlc - self.cursor.0;
+            
+            if max_move >= move_amount {
+                self.view_pos.0 += move_amount;
+            }
+            else {
+                self.view_pos.0 += max_move;
+            }
+            
+            if cursor_max_move >= move_amount {
+                self.cursor.0 += move_amount;
+            }
+            else {
+                self.cursor = self.buffer.pos_1d_to_closest_2d(self.buffer.len()+1);
+            }
+        } 
+    }
 }

src/term_ui.rs

@@ -12,10 +12,12 @@ const K_ENTER: u16 = 13;
 const K_TAB: u16 = 9;
 const K_SPACE: u16 = 32;
 const K_BACKSPACE: u16 = 127;
+const K_PAGEUP: u16 = 65519;
+const K_PAGEDOWN: u16 = 65518;
+const K_UP: u16 = 65517;
 const K_DOWN: u16 = 65516;
 const K_LEFT: u16 = 65515;
 const K_RIGHT: u16 = 65514;
-const K_UP: u16 = 65517;
 const K_ESC: u16 = 27;
 const K_CTRL_Q: u16 = 17;
 const K_CTRL_S: u16 = 19;
@@ -64,7 +66,7 @@ impl TermUI {
             let mut e = self.rb.poll_event(); // Block until we get an event
             loop {
                 match e {
-                    Ok(rustbox::Event::KeyEvent(_, key, character)) => {
+                    Ok(rustbox::Event::KeyEvent(modifier, key, character)) => {
                         //println!("      {} {} {}", modifier, key, character);
                         match key {
                             K_CTRL_Q | K_ESC => {
@@ -76,6 +78,14 @@ impl TermUI {
                                 self.editor.save_if_dirty();
                             },
                             
+                            K_PAGEUP => {
+                                self.editor.page_up();
+                            },
+                            
+                            K_PAGEDOWN => {
+                                self.editor.page_down();
+                            },
+                            
                             K_UP => {
                                 self.editor.cursor_up();
                             },

todo.md

@@ -1,4 +1,3 @@
-- Page up / page down
 - Proper handling of tab characters
 - Line number display
 - Editor info display (filename, current line/column, indentation style, etc.)